This paper presents and tests a conceptual model linking perceptions of the internal work environment and external markets to information technology (IT) worker turnover. The model focuses on organizational commitment (OC) as the primary predictor of turnover intention. We suggest that OC mediates perceptions of the workplace and external environment on turnover intention. Specifically, we hypothesize that OC mediates the influence of (1) job satisfaction, (2) perceived job characteristics, (3) perceived competitiveness of pay, and (4) perceived job alternatives on turnover intention. Also, perceived job alternatives are modeled as having a direct effect on turnover intention. Analysis provides moderate empirical support for the research model. OC and perceived job alternatives demonstrated distinct effects on turnover intention. In addition, OC mediated the influence of job satisfaction, perceived job 
characteristics, and perceived competitiveness of pay on turnover intention. Findings suggest that through cultivating positive beliefs about the job and attitudes toward the employer, managers may counter the influence of extemal markets on IT workers' turnover intention.